From 8fbd574ef065d5d71c933bbb76d8817300fbb487 Mon Sep 17 00:00:00 2001 From: Corinna Vinschen Date: Tue, 20 Feb 2007 15:48:04 +0000 Subject: [PATCH] * cygwin.din (sem_unlink): Export. * posix_ipc.cc: Include thread.h and semaphore.h. Remove TODO comment. (ipc_names): Add max_len member. Set to maximum length of the path before tacking on the prefix path. Set prefix path for named semaphors to /dev/shm, as on Linux. (enum ipc_type_t): Change sem to semaphore to avoid name conflicts. (check_path): Detect empty paths. Use ipc_names's max_len member. Use __small_sprintf to create full object path name. Special case semaphores. (ipc_cond_init): Drop superfluous strcpy. (class ipc_flock): New class to simplify file locking in subsequent code. (struct mq_hdr): Raise size of mqh_uname to allow adding a unique LUID to the name. (mq_open): Fix formatting. Create unique synchronization object names using AllocateLocallyUniqueId. (struct sem_finfo): New structure defining named semaphore file content. (sem_open): Move here. Rework implementation to allow kernel persistent implementation of POSIX named semaphores. (_sem_close): Implement sem_close. (sem_close): Move here. Just call _sem_close with do_close parameter set to true. (sem_unlink): New function. * pthread.cc (mangle_sem_name): Remove. (sem_open): Move to posix_ipc.cc. (sem_close): Ditto. * syscalls.cc (close_all_files): Call semaphore::terminate here. * thread.cc: Fix formatting. Rearrange semaphore functions so that they are close together. (semaphore::semaphore): Rework to play nicely with new named semaphore implementation. (semaphore::_terminate): Call _sem_close if semaphore is a named semaphore. (semaphore::destroy): Don't destroy named semaphores. Return EINVAL instead. (semaphore::close): Only destroy named semaphores. Return EINVAL otherwise. (semaphore::open): Rework to play nicely with new named semaphore implementation. Loop through existing semaphores to be able to return same sem_t pointer as a former call on the same named semaphore. (semaphore::getinternal): New function called from _sem_close. * thread.h (class List): Make mx and head public. (class semaphore): Fix formatting. Align method declarations with implementation in thread.cc. Add members used for named semaphores. (semaphore::terminate): New static method. * include/semaphore.h: Redefine SEM_FAILED. Fix formatting. (sem_unlink): Add declaration. * include/cygwin/version.h: Bump API minor number. --- winsup/cygwin/ChangeLog | 52 +++ winsup/cygwin/cygwin.din | 1 + winsup/cygwin/include/cygwin/version.h | 3 +- winsup/cygwin/include/semaphore.h | 17 +- winsup/cygwin/posix_ipc.cc | 237 +++++++++++++- winsup/cygwin/pthread.cc | 56 +--- winsup/cygwin/syscalls.cc | 2 + winsup/cygwin/thread.cc | 437 ++++++++++++++----------- winsup/cygwin/thread.h | 42 ++- 9 files changed, 555 insertions(+), 292 deletions(-) diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog index da11de4e9..5e427adb0 100644 --- a/winsup/cygwin/ChangeLog +++ b/winsup/cygwin/ChangeLog @@ -1,3 +1,55 @@ +2007-02-20 Corinna Vinschen + + * cygwin.din (sem_unlink): Export. + * posix_ipc.cc: Include thread.h and semaphore.h. Remove TODO + comment. + (ipc_names): Add max_len member. Set to maximum length of the path + before tacking on the prefix path. Set prefix path for named semaphors + to /dev/shm, as on Linux. + (enum ipc_type_t): Change sem to semaphore to avoid name conflicts. + (check_path): Detect empty paths. Use ipc_names's max_len member. + Use __small_sprintf to create full object path name. Special case + semaphores. + (ipc_cond_init): Drop superfluous strcpy. + (class ipc_flock): New class to simplify file locking in subsequent + code. + (struct mq_hdr): Raise size of mqh_uname to allow adding a unique + LUID to the name. + (mq_open): Fix formatting. Create unique synchronization object names + using AllocateLocallyUniqueId. + (struct sem_finfo): New structure defining named semaphore file content. + (sem_open): Move here. Rework implementation to allow kernel + persistent implementation of POSIX named semaphores. + (_sem_close): Implement sem_close. + (sem_close): Move here. Just call _sem_close with do_close parameter + set to true. + (sem_unlink): New function. + * pthread.cc (mangle_sem_name): Remove. + (sem_open): Move to posix_ipc.cc. + (sem_close): Ditto. + * syscalls.cc (close_all_files): Call semaphore::terminate here. + * thread.cc: Fix formatting. Rearrange semaphore functions so that + they are close together. + (semaphore::semaphore): Rework to play nicely with new named semaphore + implementation. + (semaphore::_terminate): Call _sem_close if semaphore is a named + semaphore. + (semaphore::destroy): Don't destroy named semaphores. Return EINVAL + instead. + (semaphore::close): Only destroy named semaphores. Return EINVAL + otherwise. + (semaphore::open): Rework to play nicely with new named semaphore + implementation. Loop through existing semaphores to be able to + return same sem_t pointer as a former call on the same named semaphore. + (semaphore::getinternal): New function called from _sem_close. + * thread.h (class List): Make mx and head public. + (class semaphore): Fix formatting. Align method declarations with + implementation in thread.cc. Add members used for named semaphores. + (semaphore::terminate): New static method. + * include/semaphore.h: Redefine SEM_FAILED. Fix formatting. + (sem_unlink): Add declaration. + * include/cygwin/version.h: Bump API minor number. + 2007-02-20 Christopher Faylor * exceptions.cc (_cygtls::signal_exit): Only call myself.exit when when diff --git a/winsup/cygwin/cygwin.din b/winsup/cygwin/cygwin.din index 4b016a465..bbb39eeaa 100644 --- a/winsup/cygwin/cygwin.din +++ b/winsup/cygwin/cygwin.din @@ -1235,6 +1235,7 @@ sem_open SIGFE sem_post SIGFE sem_timedwait SIGFE sem_trywait SIGFE +sem_unlink SIGFE sem_wait SIGFE semctl SIGFE semget SIGFE diff --git a/winsup/cygwin/include/cygwin/version.h b/winsup/cygwin/include/cygwin/version.h index fd9cf5aa3..33e5ac972 100644 --- a/winsup/cygwin/include/cygwin/version.h +++ b/winsup/cygwin/include/cygwin/version.h @@ -305,12 +305,13 @@ details. */ 164: Export shm_open, shm_unlink. 165: Export mq_close, mq_getattr, mq_notify, mq_open, mq_receive, mq_send, mq_setattr, mq_timedreceive, mq_timedsend, mq_unlink. + 166: Export sem_unlink. */ /* Note that we forgot to bump the api for ualarm, strtoll, strtoull */ #define CYGWIN_VERSION_API_MAJOR 0 -#define CYGWIN_VERSION_API_MINOR 165 +#define CYGWIN_VERSION_API_MINOR 166 /* There is also a compatibity version number associated with the shared memory regions. It is incremented when incompatible diff --git a/winsup/cygwin/include/semaphore.h b/winsup/cygwin/include/semaphore.h index 0f13c85e8..b16d13751 100644 --- a/winsup/cygwin/include/semaphore.h +++ b/winsup/cygwin/include/semaphore.h @@ -24,18 +24,19 @@ extern "C" typedef struct __sem_t {char __dummy;} *sem_t; #endif -#define SEM_FAILED 0 +#define SEM_FAILED ((sem_t *) 0) /* Semaphores */ - int sem_init (sem_t * sem, int pshared, unsigned int value); - int sem_destroy (sem_t * sem); + int sem_init (sem_t *sem, int pshared, unsigned int value); + int sem_destroy (sem_t *sem); sem_t *sem_open (const char *name, int oflag, ...); int sem_close (sem_t *sem); - int sem_wait (sem_t * sem); - int sem_trywait (sem_t * sem); - int sem_timedwait (sem_t * sem, const struct timespec *abstime); - int sem_post (sem_t * sem); - int sem_getvalue (sem_t * sem, int *sval); + int sem_unlink (const char *name); + int sem_wait (sem_t *sem); + int sem_trywait (sem_t *sem); + int sem_timedwait (sem_t *sem, const struct timespec *abstime); + int sem_post (sem_t *sem); + int sem_getvalue (sem_t *sem, int *sval); #ifdef __cplusplus } diff --git a/winsup/cygwin/posix_ipc.cc b/winsup/cygwin/posix_ipc.cc index c286b2483..492b96a49 100644 --- a/winsup/cygwin/posix_ipc.cc +++ b/winsup/cygwin/posix_ipc.cc @@ -8,12 +8,8 @@ This software is a copyrighted work licensed under the terms of the Cygwin license. Please consult the file "CYGWIN_LICENSE" for details. */ -/* TODO: POSIX semaphores are implemented in thread.cc right now. The - implementation in thread.cc disallows implementing kernel - persistent semaphores, so in the long run we should move the - implementation here, using file based shared memory instead. */ - #include "winsup.h" +#include "thread.h" #include "path.h" #include "cygerrno.h" #include "cygtls.h" @@ -29,22 +25,24 @@ details. */ #include #include #include +#include struct { const char *prefix; + const size_t max_len; const char *description; } ipc_names[] = { - { "/dev/shm", "POSIX shared memory object" }, - { "/dev/mqueue", "POSIX message queue" }, - { "/dev/sem", "POSIX semaphore" } + { "/dev/shm", CYG_MAX_PATH - 10, "POSIX shared memory object" }, + { "/dev/mqueue", CYG_MAX_PATH - 13, "POSIX message queue" }, + { "/dev/shm", CYG_MAX_PATH - 14, "POSIX semaphore" } }; enum ipc_type_t { shmem, mqueue, - sem + semaphore }; static bool @@ -69,20 +67,21 @@ check_path (char *res_name, ipc_type_t type, const char *name) return false; } /* Name must start with a single slash. */ - if (!name || name[0] != '/' || name[1] == '/') + if (!name || name[0] != '/' || name[1] == '/' || !name[1]) { debug_printf ("Invalid %s name '%s'", ipc_names[type].description, name); set_errno (EINVAL); return false; } - if (strlen (name) > CYG_MAX_PATH - sizeof (ipc_names[type].prefix)) + if (strlen (name) > ipc_names[type].max_len) { debug_printf ("%s name '%s' too long", ipc_names[type].description, name); set_errno (ENAMETOOLONG); return false; } - strcpy (res_name, ipc_names[type].prefix); - strcat (res_name, name); + __small_sprintf (res_name, "%s/%s%s", ipc_names[type].prefix, + type == semaphore ? "sem." : "", + name + 1); return true; } @@ -133,7 +132,6 @@ static int ipc_cond_init (HANDLE *pevt, const char *name) { char buf[CYG_MAX_PATH]; - strcpy (buf, wincap.has_terminal_services () ? "Global\\" : ""); __small_sprintf (buf, "%scyg_pevt/%s", wincap.has_terminal_services () ? "Global\\" : "", name); *pevt = CreateEvent (&sec_all, TRUE, FALSE, buf); @@ -195,6 +193,30 @@ ipc_cond_close (HANDLE evt) return CloseHandle (evt) ? 0 : geterrno_from_win_error (); } +class ipc_flock +{ + struct __flock64 fl; + +public: + ipc_flock () { memset (&fl, 0, sizeof fl); } + + int lock (int fd, size_t size) + { + fl.l_type = F_WRLCK; + fl.l_whence = SEEK_SET; + fl.l_start = 0; + fl.l_len = size; + return fcntl (fd, F_SETLKW, &fl); + } + int unlock (int fd) + { + if (!fl.l_len) + return 0; + fl.l_type = F_UNLCK; + return fcntl (fd, F_SETLKW, &fl); + } +}; + /* POSIX shared memory object implementation. */ extern "C" int @@ -242,7 +264,7 @@ struct mq_hdr long mqh_free; /* index of first free message */ long mqh_nwait; /* #threads blocked in mq_receive() */ pid_t mqh_pid; /* nonzero PID if mqh_event set */ - char mqh_uname[20]; /* unique name used to identify synchronization + char mqh_uname[36]; /* unique name used to identify synchronization objects connected to this queue */ struct sigevent mqh_event; /* for mq_notify() */ }; @@ -288,6 +310,7 @@ mq_open (const char *name, int oflag, ...) struct msg_hdr *msghdr; struct mq_attr *attr; struct mq_info *mqinfo; + LUID luid; char mqname[CYG_MAX_PATH]; if (!check_path (mqname, mqueue, name)) @@ -295,8 +318,9 @@ mq_open (const char *name, int oflag, ...) myfault efault; if (efault.faulted (EFAULT)) - return (mqd_t) -1; + return (mqd_t) -1; + oflag &= (O_CREAT | O_EXCL | O_NONBLOCK); created = 0; nonblock = oflag & O_NONBLOCK; oflag &= ~O_NONBLOCK; @@ -358,7 +382,14 @@ again: mqhdr->mqh_attr.mq_curmsgs = 0; mqhdr->mqh_nwait = 0; mqhdr->mqh_pid = 0; - __small_sprintf (mqhdr->mqh_uname, "cyg%016X", hash_path_name (0,mqname)); + if (!AllocateLocallyUniqueId (&luid)) + { + __seterrno (); + goto err; + } + __small_sprintf (mqhdr->mqh_uname, "cyg%016X%08x%08x", + hash_path_name (0,mqname), + luid.HighPart, luid.LowPart); mqhdr->mqh_head = 0; index = sizeof (struct mq_hdr); mqhdr->mqh_free = index; @@ -402,7 +433,7 @@ exists: { if (errno == ENOENT && (oflag & O_CREAT)) { - close(fd); + close (fd); goto again; } goto err; @@ -847,3 +878,173 @@ mq_unlink (const char *name) return 0; } +/* POSIX named semaphore implementation. Loosely based on Richard W. STEPHENS + implementation as far as sem_open is concerned, but under the hood using + the already existing semaphore class in thread.cc. Using a file backed + solution allows to implement kernel persistent named semaphores. */ + +struct sem_finfo +{ + unsigned int value; + unsigned long long hash; + LUID luid; +}; + +extern "C" sem_t * +sem_open (const char *name, int oflag, ...) +{ + int i, fd, created; + va_list ap; + mode_t mode = 0; + unsigned int value = 0; + struct __stat64 statbuff; + sem_t *sem = SEM_FAILED; + sem_finfo sf; + char semname[CYG_MAX_PATH]; + bool wasopen = false; + ipc_flock file; + + if (!check_path (semname, semaphore, name)) + return SEM_FAILED; + + myfault efault; + if (efault.faulted (EFAULT)) + return SEM_FAILED; + + created = 0; + oflag &= (O_CREAT | O_EXCL); + +again: + if (oflag & O_CREAT) + { + va_start (ap, oflag); /* init ap to final named argument */ + mode = va_arg (ap, mode_t) & ~S_IXUSR; + value = va_arg (ap, unsigned int); + va_end (ap); + + /* Open and specify O_EXCL and user-execute */ + fd = open (semname, oflag | O_EXCL | O_RDWR, mode | S_IXUSR); + if (fd < 0) + { + if (errno == EEXIST && (oflag & O_EXCL) == 0) + goto exists; /* already exists, OK */ + return SEM_FAILED; + } + created = 1; + /* First one to create the file initializes it. */ + if (!AllocateLocallyUniqueId (&sf.luid)) + { + __seterrno (); + goto err; + } + sf.value = value; + sf.hash = hash_path_name (0, semname); + if (write (fd, &sf, sizeof sf) != sizeof sf) + goto err; + sem = semaphore::open (sf.hash, sf.luid, fd, oflag, mode, value, wasopen); + if (sem == SEM_FAILED) + goto err; + /* Initialization complete, turn off user-execute bit */ + if (fchmod (fd, mode) == -1) + goto err; + /* Don't close (fd); */ + return sem; + } + +exists: + /* Open the file and fetch the semaphore name. */ + if ((fd = open (semname, O_RDWR)) < 0) + { + if (errno == ENOENT && (oflag & O_CREAT)) + goto again; + goto err; + } + /* Make certain initialization is complete */ + for (i = 0; i < MAX_TRIES; i++) + { + if (stat64 (semname, &statbuff) == -1) + { + if (errno == ENOENT && (oflag & O_CREAT)) + { + close (fd); + goto again; + } + goto err; + } + if ((statbuff.st_mode & S_IXUSR) == 0) + break; + sleep (1); + } + if (i == MAX_TRIES) + { + set_errno (ETIMEDOUT); + goto err; + } + if (file.lock (fd, sizeof sf)) + goto err; + if (read (fd, &sf, sizeof sf) != sizeof sf) + goto err; + sem = semaphore::open (sf.hash, sf.luid, fd, oflag, mode, sf.value, wasopen); + file.unlock (fd); + if (sem == SEM_FAILED) + goto err; + /* If wasopen is set, the semaphore was already opened and we already have + an open file descriptor pointing to the file. This means, we have to + close the file descriptor created in this call. It won't be stored + anywhere anyway. */ + if (wasopen) + close (fd); + return sem; + +err: + /* Don't let following function calls change errno */ + save_errno save; + + file.unlock (fd); + if (created) + unlink (semname); + if (sem != SEM_FAILED) + semaphore::close (sem); + close (fd); + return SEM_FAILED; +} + +int +_sem_close (sem_t *sem, bool do_close) +{ + sem_finfo sf; + int fd, ret = -1; + ipc_flock file; + + if (semaphore::getinternal (sem, &fd, &sf.hash, &sf.luid, &sf.value) == -1) + return -1; + if (!file.lock (fd, sizeof sf) + && lseek64 (fd, 0LL, SEEK_SET) != (_off64_t) -1 + && write (fd, &sf, sizeof sf) == sizeof sf) + ret = do_close ? semaphore::close (sem) : 0; + + /* Don't let following function calls change errno */ + save_errno save; + file.unlock (fd); + close (fd); + + return ret; +} + +extern "C" int +sem_close (sem_t *sem) +{ + return _sem_close (sem, true); +} + +extern "C" int +sem_unlink (const char *name) +{ + char semname[CYG_MAX_PATH]; + + if (!check_path (semname, semaphore, name)) + return -1; + if (unlink (semname) == -1) + return -1; + return 0; +} diff --git a/winsup/cygwin/pthread.cc b/winsup/cygwin/pthread.cc index 949bc0970..310c5d76b 100644 --- a/winsup/cygwin/pthread.cc +++ b/winsup/cygwin/pthread.cc @@ -1,6 +1,6 @@ /* pthread.cc: posix pthread interface for Cygwin - Copyright 1998, 1999, 2000, 2001, 2002, 2003 Red Hat, Inc. + Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2005, 2007 Red Hat, Inc. Originally written by Marco Fuykschot @@ -164,60 +164,6 @@ sem_destroy (sem_t * sem) return semaphore::destroy (sem); } -/* Mangle semaphore name to follow windows naming rules. Prepend "Global\" - if running on terminal service aware machine. Substitute invalid backslash - by forward slash characters, hoping not to collide. */ -static bool -mangle_sem_name (char *mangled, const char *name) -{ - myfault efault; - if (efault.faulted (EFAULT)) - return false; - if (!*name) - { - set_errno (ENOENT); - return false; - } - size_t len = strlen (cygheap->shared_prefix); - if (strlen (name) >= CYG_MAX_PATH - len) - { - set_errno (EINVAL); - return false; - } - strcpy (mangled, cygheap->shared_prefix); - char *d = mangled + len; - const char *s = name; - while (*s) - *d++ = (*s == '\\') ? '/' : *s++; - *d = '\0'; - return true; -} - -sem_t * -sem_open (const char *name, int oflag, ...) -{ - mode_t mode = 0; - unsigned int value = 0; - if (oflag & O_CREAT) - { - va_list ap; - va_start (ap, oflag); - mode = va_arg (ap, mode_t); - value = va_arg (ap, unsigned int); - va_end (ap); - } - char mangled_name[CYG_MAX_PATH]; - if (!mangle_sem_name (mangled_name, name)) - return NULL; - return semaphore::open (mangled_name, oflag, mode, value); -} - -int -sem_close (sem_t * sem) -{ - return semaphore::destroy (sem); -} - int sem_wait (sem_t * sem) { diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc index 9a1eaa1fa..0cc3a3000 100644 --- a/winsup/cygwin/syscalls.cc +++ b/winsup/cygwin/syscalls.cc @@ -109,6 +109,8 @@ close_all_files (bool norelease) { cygheap->fdtab.lock (); + semaphore::terminate (); + fhandler_base *fh; for (int i = 0; i < (int) cygheap->fdtab.size; i++) if ((fh = cygheap->fdtab[i]) != NULL) diff --git a/winsup/cygwin/thread.cc b/winsup/cygwin/thread.cc index 08eb10dd2..fc29fc19a 100644 --- a/winsup/cygwin/thread.cc +++ b/winsup/cygwin/thread.cc @@ -1,6 +1,6 @@ /* thread.cc: Locking and threading module functions - Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 Red Hat, Inc. + Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007 Red Hat, Inc. Originally written by Marco Fuykschot Substantialy enhanced by Robert Collins @@ -784,7 +784,8 @@ pthread::static_cancel_self () } DWORD -cancelable_wait (HANDLE object, DWORD timeout, const cw_cancel_action cancel_action, +cancelable_wait (HANDLE object, DWORD timeout, + const cw_cancel_action cancel_action, const enum cw_sig_wait sig_wait) { DWORD res; @@ -1734,197 +1735,6 @@ pthread_mutexattr::~pthread_mutexattr () { } -List semaphore::semaphores; - -semaphore::semaphore (int pshared, unsigned int value) -: verifyable_object (SEM_MAGIC), - shared (pshared), - currentvalue (value), - name (NULL) -{ - SECURITY_ATTRIBUTES sa = (pshared != PTHREAD_PROCESS_PRIVATE) - ? sec_all : sec_none_nih; - this->win32_obj_id = ::CreateSemaphore (&sa, value, LONG_MAX, NULL); - if (!this->win32_obj_id) - magic = 0; - - semaphores.insert (this); -} - -semaphore::semaphore (const char *sem_name, int oflag, mode_t mode, - unsigned int value) -: verifyable_object (SEM_MAGIC), - shared (PTHREAD_PROCESS_SHARED), - currentvalue (value), /* Unused for named semaphores. */ - name (NULL) -{ - if (oflag & O_CREAT) - { - SECURITY_ATTRIBUTES sa = sec_all; - security_descriptor sd; - if (allow_ntsec) - set_security_attribute (mode, &sa, sd); - this->win32_obj_id = ::CreateSemaphore (&sa, value, LONG_MAX, sem_name); - if (!this->win32_obj_id) - magic = 0; - if (GetLastError () == ERROR_ALREADY_EXISTS && (oflag & O_EXCL)) - { - __seterrno (); - CloseHandle (this->win32_obj_id); - magic = 0; - } - } - else - { - this->win32_obj_id = ::OpenSemaphore (SEMAPHORE_ALL_ACCESS, FALSE, - sem_name); - if (!this->win32_obj_id) - { - __seterrno (); - magic = 0; - } - } - if (magic) - { - name = new char [strlen (sem_name + 1)]; - if (!name) - { - set_errno (ENOSPC); - CloseHandle (this->win32_obj_id); - magic = 0; - } - else - strcpy (name, sem_name); - } - - semaphores.insert (this); -} - -semaphore::~semaphore () -{ - if (win32_obj_id) - CloseHandle (win32_obj_id); - - delete [] name; - - semaphores.remove (this); -} - -void -semaphore::_post () -{ - if (ReleaseSemaphore (win32_obj_id, 1, ¤tvalue)) - currentvalue++; -} - -int -semaphore::_getvalue (int *sval) -{ - long val; - - switch (WaitForSingleObject (win32_obj_id, 0)) - { - case WAIT_OBJECT_0: - ReleaseSemaphore (win32_obj_id, 1, &val); - *sval = val + 1; - break; - case WAIT_TIMEOUT: - *sval = 0; - break; - default: - set_errno (EAGAIN); - return -1; - } - return 0; -} - -int -semaphore::_trywait () -{ - /* FIXME: signals should be able to interrupt semaphores... - We probably need WaitForMultipleObjects here. */ - if (WaitForSingleObject (win32_obj_id, 0) == WAIT_TIMEOUT) - { - set_errno (EAGAIN); - return -1; - } - currentvalue--; - return 0; -} - -int -semaphore::_timedwait (const struct timespec *abstime) -{ - struct timeval tv; - long waitlength; - - myfault efault; - if (efault.faulted ()) - { - /* According to SUSv3, abstime need not be checked for validity, - if the semaphore can be locked immediately. */ - if (!_trywait ()) - return 0; - set_errno (EINVAL); - return -1; - } - - gettimeofday (&tv, NULL); - waitlength = abstime->tv_sec * 1000 + abstime->tv_nsec / (1000 * 1000); - waitlength -= tv.tv_sec * 1000 + tv.tv_usec / 1000; - if (waitlength < 0) - waitlength = 0; - switch (cancelable_wait (win32_obj_id, waitlength, cw_cancel_self, cw_sig_eintr)) - { - case WAIT_OBJECT_0: - currentvalue--; - break; - case WAIT_SIGNALED: - set_errno (EINTR); - return -1; - case WAIT_TIMEOUT: - set_errno (ETIMEDOUT); - return -1; - default: - debug_printf ("cancelable_wait failed. %E"); - __seterrno (); - return -1; - } - return 0; -} - -int -semaphore::_wait () -{ - switch (cancelable_wait (win32_obj_id, INFINITE, cw_cancel_self, cw_sig_eintr)) - { - case WAIT_OBJECT_0: - currentvalue--; - break; - case WAIT_SIGNALED: - set_errno (EINTR); - return -1; - default: - debug_printf ("cancelable_wait failed. %E"); - break; - } - return 0; -} - -void -semaphore::_fixup_after_fork () -{ - if (shared == PTHREAD_PROCESS_PRIVATE) - { - debug_printf ("sem %x in _fixup_after_fork", this); - /* FIXME: duplicate code here and in the constructor. */ - this->win32_obj_id = ::CreateSemaphore (&sec_none_nih, currentvalue, - LONG_MAX, NULL); - if (!win32_obj_id) - api_fatal ("failed to create new win32 semaphore, error %d"); - } -} - verifyable_object::verifyable_object (long verifyer): magic (verifyer) { @@ -3112,6 +2922,185 @@ pthread_mutexattr_settype (pthread_mutexattr_t *attr, int type) /* Semaphores */ +List semaphore::semaphores; + +semaphore::semaphore (int pshared, unsigned int value) +: verifyable_object (SEM_MAGIC), + shared (pshared), + currentvalue (value), + fd (-1), + hash (0ULL), + sem (NULL) +{ + SECURITY_ATTRIBUTES sa = (pshared != PTHREAD_PROCESS_PRIVATE) + ? sec_all : sec_none_nih; + this->win32_obj_id = ::CreateSemaphore (&sa, value, LONG_MAX, NULL); + if (!this->win32_obj_id) + magic = 0; + + semaphores.insert (this); +} + +semaphore::semaphore (unsigned long long shash, LUID sluid, int sfd, + sem_t *ssem, int oflag, mode_t mode, unsigned int value) +: verifyable_object (SEM_MAGIC), + shared (PTHREAD_PROCESS_SHARED), + currentvalue (value), /* Unused for named semaphores. */ + fd (sfd), + hash (shash), + luid (sluid), + sem (ssem) +{ + char name[CYG_MAX_PATH]; + + __small_sprintf (name, "%scyg_psem/cyg%016X%08x%08x", + wincap.has_terminal_services () ? "Global\\" : "", + hash, luid.HighPart, luid.LowPart); + this->win32_obj_id = ::CreateSemaphore (&sec_all, value, LONG_MAX, name); + if (!this->win32_obj_id) + magic = 0; + if (GetLastError () == ERROR_ALREADY_EXISTS && (oflag & O_EXCL)) + { + __seterrno (); + CloseHandle (this->win32_obj_id); + magic = 0; + } + + semaphores.insert (this); +} + +semaphore::~semaphore () +{ + if (win32_obj_id) + CloseHandle (win32_obj_id); + + semaphores.remove (this); +} + +void +semaphore::_post () +{ + if (ReleaseSemaphore (win32_obj_id, 1, ¤tvalue)) + currentvalue++; +} + +int +semaphore::_getvalue (int *sval) +{ + long val; + + switch (WaitForSingleObject (win32_obj_id, 0)) + { + case WAIT_OBJECT_0: + ReleaseSemaphore (win32_obj_id, 1, &val); + *sval = val + 1; + break; + case WAIT_TIMEOUT: + *sval = 0; + break; + default: + set_errno (EAGAIN); + return -1; + } + return 0; +} + +int +semaphore::_trywait () +{ + /* FIXME: signals should be able to interrupt semaphores... + We probably need WaitForMultipleObjects here. */ + if (WaitForSingleObject (win32_obj_id, 0) == WAIT_TIMEOUT) + { + set_errno (EAGAIN); + return -1; + } + currentvalue--; + return 0; +} + +int +semaphore::_timedwait (const struct timespec *abstime) +{ + struct timeval tv; + long waitlength; + + myfault efault; + if (efault.faulted ()) + { + /* According to SUSv3, abstime need not be checked for validity, + if the semaphore can be locked immediately. */ + if (!_trywait ()) + return 0; + set_errno (EINVAL); + return -1; + } + + gettimeofday (&tv, NULL); + waitlength = abstime->tv_sec * 1000 + abstime->tv_nsec / (1000 * 1000); + waitlength -= tv.tv_sec * 1000 + tv.tv_usec / 1000; + if (waitlength < 0) + waitlength = 0; + switch (cancelable_wait (win32_obj_id, waitlength, cw_cancel_self, cw_sig_eintr)) + { + case WAIT_OBJECT_0: + currentvalue--; + break; + case WAIT_SIGNALED: + set_errno (EINTR); + return -1; + case WAIT_TIMEOUT: + set_errno (ETIMEDOUT); + return -1; + default: + debug_printf ("cancelable_wait failed. %E"); + __seterrno (); + return -1; + } + return 0; +} + +int +semaphore::_wait () +{ + switch (cancelable_wait (win32_obj_id, INFINITE, cw_cancel_self, cw_sig_eintr)) + { + case WAIT_OBJECT_0: + currentvalue--; + break; + case WAIT_SIGNALED: + set_errno (EINTR); + return -1; + default: + debug_printf ("cancelable_wait failed. %E"); + break; + } + return 0; +} + +void +semaphore::_fixup_after_fork () +{ + if (shared == PTHREAD_PROCESS_PRIVATE) + { + debug_printf ("sem %x in _fixup_after_fork", this); + /* FIXME: duplicate code here and in the constructor. */ + this->win32_obj_id = ::CreateSemaphore (&sec_none_nih, currentvalue, + LONG_MAX, NULL); + if (!win32_obj_id) + api_fatal ("failed to create new win32 semaphore, error %d"); + } +} + +void +semaphore::_terminate () +{ + int _sem_close (sem_t *, bool); + + if (sem) + _sem_close (sem, false); +} + /* static members */ int @@ -3141,6 +3130,10 @@ semaphore::destroy (sem_t *sem) if (!is_good_object (sem)) return EINVAL; + /* It's invalid to destroy a semaphore not opened with sem_init. */ + if ((*sem)->fd != -1) + return EINVAL; + /* FIXME - new feature - test for busy against threads... */ delete (*sem); @@ -3148,8 +3141,24 @@ semaphore::destroy (sem_t *sem) return 0; } +int +semaphore::close (sem_t *sem) +{ + if (!is_good_object (sem)) + return EINVAL; + + /* It's invalid to close a semaphore not opened with sem_open. */ + if ((*sem)->fd == -1) + return EINVAL; + + delete (*sem); + delete sem; + return 0; +} + sem_t * -semaphore::open (const char *name, int oflag, mode_t mode, unsigned int value) +semaphore::open (unsigned long long hash, LUID luid, int fd, int oflag, + mode_t mode, unsigned int value, bool &wasopen) { if (value > SEM_VALUE_MAX) { @@ -3157,6 +3166,22 @@ semaphore::open (const char *name, int oflag, mode_t mode, unsigned int value) return NULL; } + /* sem_open is supposed to return the same pointer, if the same named + semaphore is opened multiple times in the same process, as long as + the semaphore hasn't been closed or unlinked in the meantime. */ + semaphores.mx.lock (); + for (semaphore *sema = semaphores.head; sema; sema = sema->next) + if (sema->fd >= 0 && sema->hash == hash + && sema->luid.HighPart == luid.HighPart + && sema->luid.LowPart == sema->luid.LowPart) + { + wasopen = true; + semaphores.mx.unlock (); + return sema->sem; + } + semaphores.mx.unlock (); + + wasopen = false; sem_t *sem = new sem_t; if (!sem) { @@ -3164,7 +3189,7 @@ semaphore::open (const char *name, int oflag, mode_t mode, unsigned int value) return NULL; } - *sem = new semaphore (name, oflag, mode, value); + *sem = new semaphore (hash, luid, fd, sem, oflag, mode, value); if (!is_good_object (sem)) { @@ -3239,6 +3264,28 @@ semaphore::getvalue (sem_t *sem, int *sval) return (*sem)->_getvalue (sval); } +int +semaphore::getinternal (sem_t *sem, int *sfd, unsigned long long *shash, + LUID *sluid, unsigned int *sval) +{ + myfault efault; + if (efault.faulted () || !is_good_object (sem)) + { + set_errno (EINVAL); + return -1; + } + if ((*sfd = (*sem)->fd) < 0) + { + set_errno (EINVAL); + return -1; + } + *shash = (*sem)->hash; + *sluid = (*sem)->luid; + /* POSIX defines the value in calls to sem_init/sem_open as unsigned, but + the sem_getvalue gets a pointer to int to return the value. Go figure! */ + return (*sem)->_getvalue ((int *)sval); +} + /* pthread_null */ pthread * pthread_null::get_null_pthread () diff --git a/winsup/cygwin/thread.h b/winsup/cygwin/thread.h index c15ded478..a1dec1ff8 100644 --- a/winsup/cygwin/thread.h +++ b/winsup/cygwin/thread.h @@ -1,6 +1,6 @@ /* thread.h: Locking and threading module definitions - Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2004 Red Hat, Inc. + Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2007 Red Hat, Inc. Written by Marco Fuykschot Major update 2001 Robert Collins @@ -208,15 +208,15 @@ template class List mx.unlock (); } + fast_mutex mx; + list_node *head; + protected: void mx_init () { if (!mx.init ()) api_fatal ("Could not create mutex for list synchronisation."); } - - fast_mutex mx; - list_node *head; }; class pthread_key: public verifyable_object @@ -633,23 +633,30 @@ class semaphore: public verifyable_object public: static bool is_good_object(sem_t const *); /* API calls */ - static int init (sem_t * sem, int pshared, unsigned int value); - static int destroy (sem_t * sem); - static sem_t *open (const char *name, int oflag, mode_t mode, - unsigned int value); - static int wait (sem_t * sem); - static int post (sem_t * sem); - static int getvalue (sem_t * sem, int *sval); - static int trywait (sem_t * sem); - static int timedwait (sem_t * sem, const struct timespec *abstime); + static int init (sem_t *sem, int pshared, unsigned int value); + static int destroy (sem_t *sem); + static sem_t *open (unsigned long long hash, LUID luid, int fd, int oflag, + mode_t mode, unsigned int value, bool &wasopen); + static int close (sem_t *sem); + static int wait (sem_t *sem); + static int post (sem_t *sem); + static int getvalue (sem_t *sem, int *sval); + static int trywait (sem_t *sem); + static int timedwait (sem_t *sem, const struct timespec *abstime); + + static int getinternal (sem_t *sem, int *sfd, unsigned long long *shash, + LUID *sluid, unsigned int *sval); HANDLE win32_obj_id; int shared; long currentvalue; - char *name; + int fd; + unsigned long long hash; + LUID luid; + sem_t *sem; semaphore (int, unsigned int); - semaphore (const char *name, int oflag, mode_t mode, unsigned int value); + semaphore (unsigned long long, LUID, int, sem_t *, int, mode_t, unsigned int); ~semaphore (); class semaphore * next; @@ -658,6 +665,10 @@ public: semaphores.fixup_after_fork (); semaphores.for_each (&semaphore::_fixup_after_fork); } + static void terminate () + { + semaphores.for_each (&semaphore::_terminate); + } private: int _wait (); @@ -667,6 +678,7 @@ private: int _timedwait (const struct timespec *abstime); void _fixup_after_fork (); + void _terminate (); static List semaphores; };